Fluid pressure accumulating apparatus

ABSTRACT

Fluid pressure accumulating apparatus in which a supply conduit is connected between a fluid pressure pump driven by an internal combustion engine and an accumulator, a control valve being provided in the supply conduit such that when the pressure within the accumulator reaches an upper limit the valve responds thereto to form a short-circuit between the supply conduit and a return conduit whereas when the pressure within the accumulator reaches a lower limit the valve responds thereto so as to remove the short circuit. The control valve can be formed as a spool valve which is urged to a closing position by a spring acting on one end thereof and is urged to an opening position by the pressure within the accumulator acting on the other end thereof.

0 United States Patent 1191 1111 3,832,095

Akima et a1. Aug. 27, 1974 [5 FLUID PRESSURE ACCUMULATING 2,981,067 4/1961 Clark etal. 137/115 x APPARATUS 3,024,732 3/1962 Nyman 1 137/115 3,029,061 4/ 1962 Hoxworth 251/634 [75] Inventors: Aklra m y Masao 3,307,568 3/1967 Gartner 137/115 Nishikawa, Niiza; Makoto S310, 3,592,211 7/ 1971 Spalding l37/625.64 X Saitama; Hiromitsu Miyahara, both O Tokyo; Yoshitaka Miyakawa, Primary ExaminerWilliam L. Freeh K g all Of Japan Assistant ExaminerRichard Sher [73] Assignee, Honda Giken KOgyO Kabushiki Attorney, Agent, or FirmWaters, Roditi, Schwartz &

Kaisha, Chuo-ku, Japan N'ssen pp 285,096 Fluid pressure accumulating apparatus in which a supply conduit is connected between a fluid pressure [30] Foreign Application priority Data pump driven by an internal combustion engine and an A 30 1971 J 46 65822 accumulator, a control valve being provided in the 1971 Japan 46-66291 supply conduit such that when the pressure within the apan accumulator reaches an upper limit the valve responds thereto to form a short-circuit between the supply (g1. 417623641514) conduit and a return conduit whereas when the pres [58] Field 251/63 sure within the accumulator reaches a lower limit the 551/63 4 valve responds thereto so as to remove the short circuit. The control valve can be formed as a spool valve 56] References Cited which is urged to a closing position by a spring acting on one end thereof and is urged to an opening position UNITED STATES PATENTS by the pressure within the accumulator acting on the 2,313,351 3/1943 Magnuson 417/307 other end thereof 2,420,394 5/1947 Gilman 137/115 2,579,051 12/1951 Rose 137/115 2 Clams, 3 Drawing Figures 1s 6 W 15 i 11 3/ 1" 23 1 1 18 1 l9 7 r n "1 -22 FLUID PRESSURE ACCUMULATING APPARATUS BRIEF SUMMARY OF THE INVENTION This invention relates to apparatus adapted for use ina vehicle such as a motorcar or the like driven by an internal combustion engine in which a fluid pressure pump such as an oil pressure pump, or the like, is driven by utilizing the foregoing internal combustion engine, and the output of the pump is accumulated in an accumulator for being ready for use.

According to the invention a supply conduit is connected between the fluid pressure and the accumulator and a control valve is interposed in the conduit so that when the pressure within the accumulator reaches an upper limit, it responds thereto so as to form a shortcircuit between the supply conduit and a return conduit whereas when the pressure within the accumulator reaches a lower limit, it responds thereto so as to eliminate the ShOI'trCII'CLIIt.

The control valve can be formed as a spool valve within a valve housing that is pushed to its closing position by a spring acting on one end thereof and to its opening position by the pressure within the accumulator acting on, the other end thereof. The control valve can also be formed as a ball valve within a valve housing and is pushed to its closing position by a spring acting on one end thereof and to its opening position by the pressure within the accumulator acting on the other end thereof. a

In further accordance with the invention, a fluid pressure operated device of open center type can be interposed in the supply conduit between the fluid pressure pump and the control valve and a fluid pressure operated device of closed center type can be interposed between the accumulator and the return conduit.

BRIEF DESCRIPTION OF THE DRAWING This invention will next be explained with reference to the accompanying drawing wherein:

FIG. 1 is a sectional side view of one embodiment of this invention;

FIG. 2 is a sectional side view of another embodiment of this invention; and

FIG. 3 is a sectional side view of amodified embodiment.

DETAILED DESCRIPTION Referring to the drawing, numeral 1 denotes an internal combustion engine mounted on a vehicle, such as a motorcar or the like, numeral 2 denotes a fluid pressure pump such as an oil pressure pump driven by the engine 1 and numeral 3 denotes a tank connected to the inlet of the pump 2, the outlet of the pump 2 being connected to an accumulator 5 through a supply conduit 4. Numeral 6 denotes a fluid pressure operated machine of closed center type, such as an oil pressure brake, which is connected at its inlet with the accumulator 5 through a conduit 7 and at its outlet with the tank 3 through a return conduit 8. Thus, the machine 6 is interposed between the accumulator 5 and the re turn conduit 8. A control valve 9 for opening and closing communication or a short circuit between the supply conduit 4 and the return conduit 8 is interposed in the supply conduit 4. The control valve 9 may be formed as either of spool valve type as shown in FIG. 1 or ball valve type as shown in FIGS. 2 and 3.

The embodiment shown in FIG. 1 will next be described as follows:

The valve 9 comprises a spool valve 11 slidable within a valve housing 10, and a valve chamber 11a containing the spool valve 11 is provided on one side with an inlet opening 12 connected to the pump 2 and an exhaust opening 13 connected to the return conduit 8 in such a manner that these openings are adjacent to one another, the chamber 11a also being provided on the other side thereof with an outlet opening 14 connected to the accumulator 5 with a ball valve type check valve 15 interposed in opening 14. An annular passage 16 is formed around the spool valve 11 'so as to provide constant communication between the inlet opening 12 and the outlet opening 14 and an annular passage 17 is formed by a groove in the outer periphery of the spool valve 11 and is in communication with the exhaust opening 13. Additionally, the spool valve 11 is provided at one end with a push spring 18 and also with a pressure chamber 20 which contains a stationary plunger 19 therein. Chamber 20 is in communication with the annular passage 16. The spool valve 11 is in contact at its other end with a plunger 21 which is in a pressure chamber 22 which in turn is in communication through a conduit 23 with the accumulator 5. Thus, the plunger 19 is subjected to the input pressure to be supplied to the accumulator 5 for pushing the valve 11 to the right, and the plunger 21 is subjected to the pressure within the accumulator 5 for pushing the valve 11 to the left, the pressure receiving area of the plunger 19 being smaller than the pressure receiving area of the plunger 21.

The operation is as follows: I

When the pressure within the accumulator 5 is zero or very low, the valve 11 is urged by the spring 18 and by the input pressure, which acts on the plunger 19 to move to the right to the position as illustrated in FIG. 1 so that the output fluid from the pump 2 is supplied through the conduit 4 to the accumulator 5 and is accumulated therein. When the pressure within the accumulator 5 rises and reaches a predetermined upper limit, the pressure acts on the valve 11 through the plunger 21 from the pressure chamber 22 side and moves the valve 1 1 to the left whereby the annular passages l6, 17 are brought into communication with one another and the input pressure within the annular passage 16 begins to drop. Thereby, the input pressure acting on the plunger 19 is rapidly decreased, and in accordance therewith the pushing force to the right on the valve 11 is rapidly decreased and thereby the valve is rapidly moved to the left. In this way, the annular passage 16, 17 are brought into greater registry with one another, so that the output of the pump 2 flows out therethrough into theretum conduit 8 and is returned to the tank 3 and thus the supply of the pressure to the accumulator 5 is suspended by virtue of the short circuit which is formed. If, then, the pressure fluid within that the force acting on the plunger 19 is rapidly increased, whereby the valve 11 is rapidly moved to the right to return to the illustrated position for being ready for the next operation.

FIG. 2 shows a modified embodiment of the control valve 9 and herein the same numerals will be used for the same structure as illustrated in FIG. 1 and prime numerals for modified structure. The construction comprises a ball valve 11 within a valve housing 10'. A valve chamber 110 containing the ball valve 11 is provided with an inlet opening 12' connected to the pump 2 and an exhaust opening 13' connected to the return conduit 8 in such a manner that the openings 12, 13 are located on the opposite sides of the ball valve 11' and, the valve chamber 11a is also provided on the side of inlet opening 12' with an outlet opening 14 connected to the accumulator 5. Additionally, the ball valve 11' is provided on one side with a spring 18' by which it is pushed to its closing position, and on the other side with a pressure chamber 22 and a plunger 21 contained therein, the pressure chamber 22' being connected to the accumulator through a conduit 23'- having an orifice 30. Additionally, there is provided within the valve housing a pilotvalve which serves to provide communication between the pressure chamber 22 and the valve chamber 11a, the pilot valve comprising a ball valve 25 urged by a spring 24 to a closing position and contained in a valve chamber 26. The chamber 26 is connected at its rear portion to the pressure chamber 22' and at its front portion to the valve chamber 11a. Additionally, a plunger 29 is movable back and forth in chamber 26-both by the pressure within a pressure chamber 27 connected to the valve chamber Ila, and by a spring 28.

The operation will next be explained as follows:

If the pressure within the accumulator 5 rises and reaches the upper limit, the interior of the pressure chamber 22 is subjected to this high pressure, so that the plunger 21 is pushed thereby and is moved to the right in the drawing, whereby the ball valve 11 is pushed against the action of the pressure within the valve chamber Ila and that of the spring 18, and the valve 11' is opened. Accordingly, the output of the pump 2 is set for exhaust from the valve chamber 11a through the ball valve 11 into the return conduit 8. By this exhaust, the pressure within the ball valve chamber Ila is rapidly decreased and the force exerted on the back of the ball valve 11 is further decreased as a result of which the ball valve 11' is moved to the right rapidly and reaches a fully open, short-circuit position. In this case, the pressure within the pressure chamber 27 is also lowered and thereby the pushing force of plunger 29 acting on the ball valve 25 is increased but at that time the accumulator pressure and the force of spring 24 acting on the opposite surface of the ball valve 25 are greater than the force on the plunger 29 and thereby the ball valve 25 is kept closed. When the pressure within the accumulator 5 is lowered and reaches the lower limit, the pressure within the pressure chamber 26 is decreased, so that the ball valve 25 is opened by thepushing action of the plunger 29 and the fluid within the valve chamber 26 flows into the valve chamber lla through the valve 25 and then is exhausted via the exhaust opening 13 to the tank 3. By this exhaust, the pressure within the valve chamber 26 and that within the pressure chamber 22' are rapidly lowered and thereby the ball valve 11 is closed by the pushing action of the spring 18'. This valve closing, the pressure within the valve chamber 11a is increased, so that the ball valve 1 l is further pushed in its closing direction to eliminate the shortcircuit. In this case, the pressure within the pressure chamber 27 is also increased and the plunger 29 is retreated thereby against the action of the spring 28, so that the ball valve 25 is again closed for being ready for the next operation.

FIG. 3 shows a modified version of FIG. 2 in which the outlet side of the ball valve 25 constituting the pilot valve is connected through a passage 31 directly to the exhaust opening 13, instead of being connected through the valve chamber 11a, and the pressure within the accumulator 5 is also applied to the interior of the pressure chamber 27 in front of the plunger 29 through a conduit 32, so that when the pressure within the accumulator 5 reaches the lower limit, the pressure in front of the plunger 29 is also lowered so that the plunger 29 may be easily advanced for opening the pilot valve 25 whereby the operation becomes highly sensitive.

Thus, according to this invention, the output fluid of the pump 2 is passed to the return conduit 8 when the pressure within the accumulator 5 reaches its upper limit and the output fluid of the pump 2 is passed to the accumulator 5 when the pressure within the accumulator 5 reaches its lower limit, whereby the pressure within the accumulator 5 is automatically maintained between the upper limit and the lower limit and the fluid pressure operated device 6 can be always operated with certainty. Additionally, when the pressure within the accumulator 5 reaches its upper limit, the pump is released from any load and thus wastage of power can be eliminated and any unnecessary rise in fluid temperature can be prevented. The control valve can be operated simply and accurately by being formed as a spool valve or a ball valve.

Additionally, according to an additional feature of this invention, the foregoing circuit arrangement can be provided with two kinds of fluid pressure operated devices, that is, a fluid pressure operated device of open center type which in ordinary operation permits pressure fluid to flow therethrough, and a fluid pressure operated device of closed center type which in ordinary operations prevents the pressure fluid from flowing therethrough, the arrangement being such that either of these devices can be operated at any desired time. Namely, the closed center type device 6 is interposed between the accumulator 5 and the return conduit 8 as mentioned before, and an open center type device 33 is interposed in the supply circuit 4 between the pump 2 and the control valve 9. When the devices 5 and 33 are so provided as above, the device 33 does not obstruct any supply of pressure fluid from the pump 2 to the control valve 9 in the ordinary case because it is of the type that ordinarily allows pressure fluid to flow therethrough, but it can be operated at any desired time by being supplied with a pressure fluid from the pump 2. Additionally, the device 6 does not exhaust the pressure fluid within the accumulator 5 to the return conduit 8 therethrough in the ordinary case because it is of the type that normally prevents pressure fluid from passing therethrough, but it can be operated at any desired time by being supplied with pressure fluid from the accumulator 5.

Relative to the above use of the expressions open center and closed center, types of these devices are respectively shown in US. Pat. Nos. 3,233,408 and r 3,272,085 of Feb. 8, 1966 and Sept. 13, 1966 respectively.

Thus, according to this feature of this invention, the foregoing circuit arrangement can be provided, without being affected in its control operation, with two kinds of fluid pressure operated devices, so that these devices can be operated at any desired time, and a separate circuit construction for each device is unnecessary and the construction becomes simple.

What is claimed is:

1. Fluid pressure accumulating apparatus in combination with a reservoir, a fluid pressure pump coupled to said reservoir and driven by an internal combustion engine, and an accumulator, said apparatus comprising a supply conduit connected between the pump and accumulator, an exhaust conduit coupled to said reservoir, and control valve means coupled to said conduits and the accumulator for forming a short circuit between the supply conduit and exhaust conduit when the accumulator is at an upper limit pressure and for removing the short circuit when the accumulator is at a lower limit pressure, said control valve means comprising a valve housing, said supply conduit leading into said housing, said accumulator being connected to said housing, a valve member in said housing controlling fluid flow between the supply conduit and the accumulator, spring means acting on the valve member to urge the valve member in one direction to close communication between the supply conduit of the exhaust conduit and remove the short circuit, and means for applying the pressure of the fluid within the accumulator on the valve member to urge the same in opposite direction to form said short circuit, said valve member being a spool valve, said valve housing having an annular passage leading to said supply conduit and to said accumulator, said spool valve having an annular passage in communication with said exhaust conduit, said spool valve being in a position during short circuit in which the annular passage in the spool valve is in communication with the annular passage in the housing, said valve means further comprising a first plunger in contact with said valve member and subjected to the pressure of the fluid in the accumulator to urge the valve member in said opposite direction, said spool valve having a bore in communication with the annular passage in the housing whereby the bore is at the pressure prevailing in the supply conduit, a stationary second plunger extending into said bore such that the pressure of the fluid in the bore acts to urge the spool valve in said one direction, said first plunger having a greater cross-sectional area than the stationary second plunger, and a check valve in said housing between the annular passage in the housing and the accumulator.

2. Apparatus as claimed in claim 1 comprising a fluid pressure operated device of open center type interposed in said supply conduit between the pump and the control valve means, and a second fluid pressure operated device of closed center type interposed between the accumulator and the exhaust conduit. 

1. Fluid pressure accumulating apparatus in combination with a reservoir, a fluid pressure pump coupled to said reservoir and driven by an internal combustion engine, and an accumulator, said apparatus comprising a supply conduit connected between the pump and accumulator, an exhaust conduit coupled to said reservoir, and control valve means coupled to said conduits and the accumulator for forming a short circuit between the supply conduit and exhaust conduit when the accumulator is at an upper limit pressure and for removing the short circuit when the accumulator is at a lower limit pressure, said control valve means comprising a valve housing, said supply conduit leading into said housing, said accumulator being connected to said housing, a valve member in said housing controlling fluid flow between the supply conduit and the accumulator, spring means acting on the valve member to urge the valve member in one direction to close communication between the supply conduit of the exhaust conduit and remove the short circuit, and means for applying the pressure of the fluid within the accumulator on the valve member to urge the same in opposite direction to form said short circuit, said valve member being a spool valve, said valve housing having an annular passage leading to said supply conduit and to said accumulator, said spool valve having an annular passage in communication with said exhaust conduit, said spool valve being in a position during short circuit in which the annular passage in the spool valve is in communication with the annular passage in the housing, said valve means further comprising a first plunger in contact with said valve member and subjected to the pressure of the fluid in the accumulator to urge the valve member in said opposite direction, said spool valve having a bore in communication with the annular passage in the housing whereby the bore is at the pressure prevailing in the supply conduit, a stationary second plunger extending into said bore such that the pressure of the fluid in the bore acts to urge the spool valve in said one direction, said first plunger having a greater cross-sectional area than the stationary second plunger, and a check valve in said housing between the annular passage in the housing and the accumulator.
 2. Apparatus as claimed in claim 1 comprising a fluid pressure operated device of open center type interposed in said supply conduit between the pump and the control valve means, and a second fluid pressure operated device of closed center type interposed between the accumulator and the exhaust conduit. 